Com-Pac Yacht Owners Association

Com-Pac Model Specific Discussions => Horizon Cats and Horizon Day Cats => Topic started by: soulsail on September 14, 2025, 12:21:54 PM

Title: Cut out in the mast - is this safe?
Post by: soulsail on September 14, 2025, 12:21:54 PM
I'm considering a Horizon. It's an otherwise nice boat but the current owner has made a cutout in the mast (see picture attached), apparently to install a clamp to prevent the boom from dropping too low.

The cut does not look professionally done and has rough, sharp edges. There could be potential for stress concentration zones around it when mast is under loads.

Any thoughts on such a cut and if I should pass on this boat due to this issue? Appreciate any help.
Title: Re: Cut out in the mast - is this safe?
Post by: bruce on September 14, 2025, 06:57:14 PM
Not sure what you understand as "too low". Is this below the hinge, and the boom, sail, and gaff, can be can still be stowed on the mast stub before lowering the mast as required, or something to hold the boom up to a height when sailing? Neither is needed, or could be accomplished much less invasively if someone felt it necessary. I think the mast is probably still serviceable, my bigger concern is what else has he done? His workmanship is garbage.
Title: Re: Cut out in the mast - is this safe?
Post by: soulsail on September 14, 2025, 07:44:51 PM
This cutout is done below the boom hinge. I don't fully understand the reasoning behind this cutout, but regardless the risk of stress cracks is high at these sharp cut edges. Maybe it can be salvaged by smoothing the edges and welding... but so unfortunate. I wished a professional was asked to do this work or better not done at all on an otherwise nice boat.
Title: Re: Cut out in the mast - is this safe
Post by: bruce on September 14, 2025, 08:24:55 PM
If the clamp idea was just your guess, he may have done it as a mast gate. The sail slugs and gooseneck slides are easily removed by removing the hinge pivot bolts and lifting the mast off the stub. No need for a mast gate.

There isn't a lot of stress on the stub. It can be welded of course. Damage to the mast track is common on the Com-Pac catboats when the mast is lowered without the spars and sail below the hinge. Com-Pac sold repair bars that would reinforce damaged areas, affixed with machine screws. Pretty marginal, but it helps. You could do something like that if you were concerned. Welding would be better.

This thread mentions the repair plates, reply #6. As you can see, nothing fancy.
https://cpyoa.com/forum/index.php?topic=8993.msg66877#msg66877

I wouldn't pass on the boat if it was otherwise good. Again, I'd be most concerned about what other bad ideas he implemented.
Title: Re: Cut out in the mast - is this safe?
Post by: alsantini on September 29, 2025, 11:44:09 AM
I repaired a smaller cut in my Eclipse when I purchased it.  I filed it down to eliminate sharp edges, bought some thin aluminum at a hardware store, and some machine screws.  I drilled and tapped the mast in 4 places, so the repair would be held on top, bottom and (2 screws) on the side.  I formed the replacement piece to the mast and screwed it down.  Trailer sailed the Eclipse for 10 years with no problems.  Easy fix.